From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: [PATCH 5/8] ALSA: opl3: Hardening for potential Spectre v1 Date: Tue, 24 Apr 2018 09:56:16 +0200 Message-ID: <20180424075619.29602-6-tiwai@suse.de> References: <20180424075619.29602-1-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id E1CC526722C for ; Tue, 24 Apr 2018 09:56:42 +0200 (CEST) In-Reply-To: <20180424075619.29602-1-tiwai@suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org Cc: Dan Carpenter List-Id: alsa-devel@alsa-project.org As the recent Smatch warned, one place in OPL3 driver may expand the array directly from the user-space value with speculation: sound/drivers/opl3/opl3_synth.c:476 snd_opl3_set_voice() warn: potential spectre issue 'snd_opl3_regmap' This patch puts array_index_nospec() for hardening against it. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter Signed-off-by: Takashi Iwai --- sound/drivers/opl3/opl3_synth.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sound/drivers/opl3/opl3_synth.c b/sound/drivers/opl3/opl3_synth.c index ddcc1a325a61..42920a243328 100644 --- a/sound/drivers/opl3/opl3_synth.c +++ b/sound/drivers/opl3/opl3_synth.c @@ -21,6 +21,7 @@ #include #include +#include #include #include @@ -448,7 +449,7 @@ static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * v { unsigned short reg_side; unsigned char op_offset; - unsigned char voice_offset; + unsigned char voice_offset, voice_op; unsigned short opl3_reg; unsigned char reg_val; @@ -473,7 +474,9 @@ static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * v voice_offset = voice->voice - MAX_OPL2_VOICES; } /* Get register offset of operator */ - op_offset = snd_opl3_regmap[voice_offset][voice->op]; + voice_offset = array_index_nospec(voice_offset, MAX_OPL2_VOICES); + voice_op = array_index_nospec(voice->op, 4); + op_offset = snd_opl3_regmap[voice_offset][voice_op]; reg_val = 0x00; /* Set amplitude modulation (tremolo) effect */ -- 2.16.3